1. Field of the Invention
The invention relates in general to reproduction technology and particularly point-by-point film exposure for recording rasters, continuous tone images and linework characters in scanner technology wherein the exposure spot is defined by the intensity of the light, the size of the spot, the edge steepness or focus and the intensity distribution which are controlled so as to achieve uniform and high contrast exposures.
2. Description of the Prior Art
Scanners wherein raster points are exposed onto photographic material using multitrack recording elements are employed at the present time in printing technology when producing raster color separations on photographic materials. This type of recording with a plurality of light beams mounted next to each other is disclosed, for example, in U.S. Pat. No. 3,725,574 which system requires a precise adjustment of the sub-beams so that the line contact prevails between the individual sub-beams and so that unexposed strips do not result on the film.
Using present state of the art scanner technology the adjustment and observation of the point properties is indirectly monitored by using test exposures and the focus or sharpness of the beam is also measured or respectively is set by using a distance template whereby constant monitoring on the part of the user is required. Particularly when evaluating a false or undesired intensity distribution on the basis of the exposure result is only approximately possible because of the convolution of the gradation curve of the film and such evaluations result in a considerable loss of material and loss of time.